The mayor cannot stop federal authorities from making arrests, Newsom told about 300 mostly Latino members of St. Peter's Church and other religious groups supporting immigrants. But no San Francisco employee will help with immigration enforcement.

“I will not allow any of my department heads or anyone associated with this city to cooperate in any way shape or form with these raids,” Newsom declared. “We are a sanctuary city, make no mistake about it.”

Newsom’s strategy brings to mind one of my longstanding policy pipe dreams: that California, or some other state, might declare a separate peace in the drug war. “Yes,” the argument would go, “California does not have the power to repeal federal laws. But it does have to the power to dispose of its own budget and use its own state and city employees as it sees fit. From this point forward, if the federal government wishes to enforce federal drug laws in California, it will have to do so with federal tax dollars and employees. No state tax dollars or state employees will participate in fighting the drug war.” Essentially, the strategy would extend the state's current treatment of medical marijuana to drugs in general.

Of course, the danger is that the federal government would strong-arm California into doing its bidding by threatening to withhold highway funds and other pork-barrel spending. But this is why California would be the ideal state for my strategy: with 53 U.S. representatives, it has the largest congressional delegation, which would presumably resist such budgetary tactics. Even Californian representatives who are drug warriors would have a difficult time depriving their home state of funds because of what the state government had done.